In the related art, an automatic speed changer of a hoist including two clutch mechanisms and enabling high-speed hoisting when no load is applied is developed. However, since a contact-type switching system in which a transmission plate is mechanically slid is employed, there is a problem that an internal resistance at the time of switching is large, and hence the operability is not good. Therefore, a hoist with built-in load sensitive automatic speed change device in which an operator needs not to perform a cumbersome gear-shifting operation every time when the state of a load changes, and when hoisting a predetermined load or larger, is allowed to perform power transmission between a low-speed side rotating member and an output member smoothly, and hence an impact or a noise at the time of switching may be reduced is proposed by the present applicant (Patent Literature 1). Also, in the hoist described above, a device which realizes reduction in size of the load sensitive automatic speed change device is also proposed by the present applicant (Patent Literature 2) (Patent Literature 3).    Patent Literature 1: JP-A-2010-116957    Patent Literature 2: JP-A-2011-106666    Patent Literature 3: JP-A-2012-52572